Aircon clutch engaging intermittently

[Trawa]

I'm at the wits' end with this one so bear with me...

Aircon been regassed and checked for leaks, all is perfect. Blows 5°C air when it works but after running for about 10-15 minutes compressor clutch disengages and won't engage again until the car has been shut off and sat for 10-15 mins after which it works again for 10-15mins and shuts off again.
Happens both on cold and warm starts so not engine temp related.
If temperature is set to LO with the engine idling both fans will start running but clutch still won't engage. Checked fuses and relays, everything is okay.
Had it scanned for codes but nothing AC related came up.
What can it be? Sensor failure? Clutch on its last legs?

 

[F6HAD]

The compressor has a thermal cut off switch. Either that is bad or the compressor is overheating in which case the cut off is doing its job. Often easier just to change the compressor for a cheap replacement.

 

[Trawa]

Is that something that can be checked with HDS or do I have to chase the wiring with a multimeter?

 

[F6HAD]

It’s not the wiring, there is a small black connector on the compressor which is for the thermal switch. If you’re able to change it without breaking then do that but it might actually be doing its job and your compressor is overheating. You can actually bypass it by joining the 2 wires together but then ask yourself if you should be doing that if in fact the compressor is about to go bang.

Google it, plenty of info and videos online.

 

[Trawa]

Yeah that's what I'm asking. Is there any way to check the actual readout of the sensor either via HDS or by checking the resistance on the plug or something.
Seems a bit odd to me because if I set the temp to say 18c instead of LO it can work fine for much longer periods of time.

Do you know if the thermal cutoff will reset by itself once the temp drops enough or does it require the ignition to be cycled? I noticed that turning the climate control off with the engine running doesn't seem to make it work again and that should cool down the compressor too.

 

[Trawa]

Checked once again, once the compressor disengages poking the clutch does not engage it again (spins for about a second and disengages again). Letting the compressor cool down with the engine idling does not do anything.
After cycling the ignition and aircon neither fans or clutch come on with the AC set to LO.

 

[Trawa]

Fixed the issue, for future reference the culprit was a worn down compressor clutch.

Once heated up the metal expanded and the air gap increased enough to stop the clutch from engaging, the fix is to remove a shim from under the clutch plate to bring the gap back into spec or replace the entire clutch and pulley with a new one.

 

[F6HAD]

You can use a feeler gauge to check for gap normally